1// Locale support (codecvt) -*- C++ -*- 2 3// Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 4// 2009, 2010, 2011 Free Software Foundation, Inc. 5// 6// This file is part of the GNU ISO C++ Library. This library is free 7// software; you can redistribute it and/or modify it under the 8// terms of the GNU General Public License as published by the 9// Free Software Foundation; either version 3, or (at your option) 10// any later version. 11 12// This library is distributed in the hope that it will be useful, 13// but WITHOUT ANY WARRANTY; without even the implied warranty of 14// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15// GNU General Public License for more details. 16 17// Under Section 7 of GPL version 3, you are granted additional 18// permissions described in the GCC Runtime Library Exception, version 19// 3.1, as published by the Free Software Foundation. 20 21// You should have received a copy of the GNU General Public License and 22// a copy of the GCC Runtime Library Exception along with this program; 23// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 24// <http://www.gnu.org/licenses/>. 25 26/** @file bits/codecvt.h 27 * This is an internal header file, included by other library headers. 28 * Do not attempt to use it directly. @headername{locale} 29 */ 30 31// 32// ISO C++ 14882: 22.2.1.5 Template class codecvt 33// 34 35// Written by Benjamin Kosnik <bkoz@redhat.com> 36 37#ifndef _CODECVT_H 38#define _CODECVT_H 1 39 40#pragma GCC system_header 41 42namespace std _GLIBCXX_VISIBILITY(default) 43{ 44_GLIBCXX_BEGIN_NAMESPACE_VERSION 45 46 /// Empty base class for codecvt facet [22.2.1.5]. 47 class codecvt_base 48 { 49 public: 50 enum result 51 { 52 ok, 53 partial, 54 error, 55 noconv 56 }; 57 }; 58 59 /** 60 * @brief Common base for codecvt functions. 61 * 62 * This template class provides implementations of the public functions 63 * that forward to the protected virtual functions. 64 * 65 * This template also provides abstract stubs for the protected virtual 66 * functions. 67 */ 68 template<typename _InternT, typename _ExternT, typename _StateT> 69 class __codecvt_abstract_base 70 : public locale::facet, public codecvt_base 71 { 72 public: 73 // Types: 74 typedef codecvt_base::result result; 75 typedef _InternT intern_type; 76 typedef _ExternT extern_type; 77 typedef _StateT state_type; 78 79 // 22.2.1.5.1 codecvt members 80 /** 81 * @brief Convert from internal to external character set. 82 * 83 * Converts input string of intern_type to output string of 84 * extern_type. This is analogous to wcsrtombs. It does this by 85 * calling codecvt::do_out. 86 * 87 * The source and destination character sets are determined by the 88 * facet's locale, internal and external types. 89 * 90 * The characters in [from,from_end) are converted and written to 91 * [to,to_end). from_next and to_next are set to point to the 92 * character following the last successfully converted character, 93 * respectively. If the result needed no conversion, from_next and 94 * to_next are not affected. 95 * 96 * The @a state argument should be initialized if the input is at the 97 * beginning and carried from a previous call if continuing 98 * conversion. There are no guarantees about how @a state is used. 99 * 100 * The result returned is a member of codecvt_base::result. If 101 * all the input is converted, returns codecvt_base::ok. If no 102 * conversion is necessary, returns codecvt_base::noconv. If 103 * the input ends early or there is insufficient space in the 104 * output, returns codecvt_base::partial. Otherwise the 105 * conversion failed and codecvt_base::error is returned. 106 * 107 * @param state Persistent conversion state data. 108 * @param from Start of input. 109 * @param from_end End of input. 110 * @param from_next Returns start of unconverted data. 111 * @param to Start of output buffer. 112 * @param to_end End of output buffer. 113 * @param to_next Returns start of unused output area. 114 * @return codecvt_base::result. 115 */ 116 result 117 out(state_type& __state, const intern_type* __from, 118 const intern_type* __from_end, const intern_type*& __from_next, 119 extern_type* __to, extern_type* __to_end, 120 extern_type*& __to_next) const 121 { 122 return this->do_out(__state, __from, __from_end, __from_next, 123 __to, __to_end, __to_next); 124 } 125 126 /** 127 * @brief Reset conversion state. 128 * 129 * Writes characters to output that would restore @a state to initial 130 * conditions. The idea is that if a partial conversion occurs, then 131 * the converting the characters written by this function would leave 132 * the state in initial conditions, rather than partial conversion 133 * state. It does this by calling codecvt::do_unshift(). 134 * 135 * For example, if 4 external characters always converted to 1 internal 136 * character, and input to in() had 6 external characters with state 137 * saved, this function would write two characters to the output and 138 * set the state to initialized conditions. 139 * 140 * The source and destination character sets are determined by the 141 * facet's locale, internal and external types. 142 * 143 * The result returned is a member of codecvt_base::result. If the 144 * state could be reset and data written, returns codecvt_base::ok. If 145 * no conversion is necessary, returns codecvt_base::noconv. If the 146 * output has insufficient space, returns codecvt_base::partial. 147 * Otherwise the reset failed and codecvt_base::error is returned. 148 * 149 * @param state Persistent conversion state data. 150 * @param to Start of output buffer. 151 * @param to_end End of output buffer. 152 * @param to_next Returns start of unused output area. 153 * @return codecvt_base::result. 154 */ 155 result 156 unshift(state_type& __state, extern_type* __to, extern_type* __to_end, 157 extern_type*& __to_next) const 158 { return this->do_unshift(__state, __to,__to_end,__to_next); } 159 160 /** 161 * @brief Convert from external to internal character set. 162 * 163 * Converts input string of extern_type to output string of 164 * intern_type. This is analogous to mbsrtowcs. It does this by 165 * calling codecvt::do_in. 166 * 167 * The source and destination character sets are determined by the 168 * facet's locale, internal and external types. 169 * 170 * The characters in [from,from_end) are converted and written to 171 * [to,to_end). from_next and to_next are set to point to the 172 * character following the last successfully converted character, 173 * respectively. If the result needed no conversion, from_next and 174 * to_next are not affected. 175 * 176 * The @a state argument should be initialized if the input is at the 177 * beginning and carried from a previous call if continuing 178 * conversion. There are no guarantees about how @a state is used. 179 * 180 * The result returned is a member of codecvt_base::result. If 181 * all the input is converted, returns codecvt_base::ok. If no 182 * conversion is necessary, returns codecvt_base::noconv. If 183 * the input ends early or there is insufficient space in the 184 * output, returns codecvt_base::partial. Otherwise the 185 * conversion failed and codecvt_base::error is returned. 186 * 187 * @param state Persistent conversion state data. 188 * @param from Start of input. 189 * @param from_end End of input. 190 * @param from_next Returns start of unconverted data. 191 * @param to Start of output buffer. 192 * @param to_end End of output buffer. 193 * @param to_next Returns start of unused output area. 194 * @return codecvt_base::result. 195 */ 196 result 197 in(state_type& __state, const extern_type* __from, 198 const extern_type* __from_end, const extern_type*& __from_next, 199 intern_type* __to, intern_type* __to_end, 200 intern_type*& __to_next) const 201 { 202 return this->do_in(__state, __from, __from_end, __from_next, 203 __to, __to_end, __to_next); 204 } 205 206 int 207 encoding() const throw() 208 { return this->do_encoding(); } 209 210 bool 211 always_noconv() const throw() 212 { return this->do_always_noconv(); } 213 214 int 215 length(state_type& __state, const extern_type* __from, 216 const extern_type* __end, size_t __max) const 217 { return this->do_length(__state, __from, __end, __max); } 218 219 int 220 max_length() const throw() 221 { return this->do_max_length(); } 222 223 protected: 224 explicit 225 __codecvt_abstract_base(size_t __refs = 0) : locale::facet(__refs) { } 226 227 virtual 228 ~__codecvt_abstract_base() { } 229 230 /** 231 * @brief Convert from internal to external character set. 232 * 233 * Converts input string of intern_type to output string of 234 * extern_type. This function is a hook for derived classes to change 235 * the value returned. @see out for more information. 236 */ 237 virtual result 238 do_out(state_type& __state, const intern_type* __from, 239 const intern_type* __from_end, const intern_type*& __from_next, 240 extern_type* __to, extern_type* __to_end, 241 extern_type*& __to_next) const = 0; 242 243 virtual result 244 do_unshift(state_type& __state, extern_type* __to, 245 extern_type* __to_end, extern_type*& __to_next) const = 0; 246 247 virtual result 248 do_in(state_type& __state, const extern_type* __from, 249 const extern_type* __from_end, const extern_type*& __from_next, 250 intern_type* __to, intern_type* __to_end, 251 intern_type*& __to_next) const = 0; 252 253 virtual int 254 do_encoding() const throw() = 0; 255 256 virtual bool 257 do_always_noconv() const throw() = 0; 258 259 virtual int 260 do_length(state_type&, const extern_type* __from, 261 const extern_type* __end, size_t __max) const = 0; 262 263 virtual int 264 do_max_length() const throw() = 0; 265 }; 266 267 268 269 /** 270 * @brief Primary class template codecvt. 271 * @ingroup locales 272 * 273 * NB: Generic, mostly useless implementation. 274 * 275 */ 276 template<typename _InternT, typename _ExternT, typename _StateT> 277 class codecvt 278 : public __codecvt_abstract_base<_InternT, _ExternT, _StateT> 279 { 280 public: 281 // Types: 282 typedef codecvt_base::result result; 283 typedef _InternT intern_type; 284 typedef _ExternT extern_type; 285 typedef _StateT state_type; 286 287 protected: 288 __c_locale _M_c_locale_codecvt; 289 290 public: 291 static locale::id id; 292 293 explicit 294 codecvt(size_t __refs = 0) 295 : __codecvt_abstract_base<_InternT, _ExternT, _StateT> (__refs) { } 296 297 explicit 298 codecvt(__c_locale __cloc, size_t __refs = 0); 299 300 protected: 301 virtual 302 ~codecvt() { } 303 304 virtual result 305 do_out(state_type& __state, const intern_type* __from, 306 const intern_type* __from_end, const intern_type*& __from_next, 307 extern_type* __to, extern_type* __to_end, 308 extern_type*& __to_next) const; 309 310 virtual result 311 do_unshift(state_type& __state, extern_type* __to, 312 extern_type* __to_end, extern_type*& __to_next) const; 313 314 virtual result 315 do_in(state_type& __state, const extern_type* __from, 316 const extern_type* __from_end, const extern_type*& __from_next, 317 intern_type* __to, intern_type* __to_end, 318 intern_type*& __to_next) const; 319 320 virtual int 321 do_encoding() const throw(); 322 323 virtual bool 324 do_always_noconv() const throw(); 325 326 virtual int 327 do_length(state_type&, const extern_type* __from, 328 const extern_type* __end, size_t __max) const; 329 330 virtual int 331 do_max_length() const throw(); 332 }; 333 334 template<typename _InternT, typename _ExternT, typename _StateT> 335 locale::id codecvt<_InternT, _ExternT, _StateT>::id; 336 337 /// class codecvt<char, char, mbstate_t> specialization. 338 template<> 339 class codecvt<char, char, mbstate_t> 340 : public __codecvt_abstract_base<char, char, mbstate_t> 341 { 342 public: 343 // Types: 344 typedef char intern_type; 345 typedef char extern_type; 346 typedef mbstate_t state_type; 347 348 protected: 349 __c_locale _M_c_locale_codecvt; 350 351 public: 352 static locale::id id; 353 354 explicit 355 codecvt(size_t __refs = 0); 356 357 explicit 358 codecvt(__c_locale __cloc, size_t __refs = 0); 359 360 protected: 361 virtual 362 ~codecvt(); 363 364 virtual result 365 do_out(state_type& __state, const intern_type* __from, 366 const intern_type* __from_end, const intern_type*& __from_next, 367 extern_type* __to, extern_type* __to_end, 368 extern_type*& __to_next) const; 369 370 virtual result 371 do_unshift(state_type& __state, extern_type* __to, 372 extern_type* __to_end, extern_type*& __to_next) const; 373 374 virtual result 375 do_in(state_type& __state, const extern_type* __from, 376 const extern_type* __from_end, const extern_type*& __from_next, 377 intern_type* __to, intern_type* __to_end, 378 intern_type*& __to_next) const; 379 380 virtual int 381 do_encoding() const throw(); 382 383 virtual bool 384 do_always_noconv() const throw(); 385 386 virtual int 387 do_length(state_type&, const extern_type* __from, 388 const extern_type* __end, size_t __max) const; 389 390 virtual int 391 do_max_length() const throw(); 392 }; 393 394#ifdef _GLIBCXX_USE_WCHAR_T 395 /// class codecvt<wchar_t, char, mbstate_t> specialization. 396 template<> 397 class codecvt<wchar_t, char, mbstate_t> 398 : public __codecvt_abstract_base<wchar_t, char, mbstate_t> 399 { 400 public: 401 // Types: 402 typedef wchar_t intern_type; 403 typedef char extern_type; 404 typedef mbstate_t state_type; 405 406 protected: 407 __c_locale _M_c_locale_codecvt; 408 409 public: 410 static locale::id id; 411 412 explicit 413 codecvt(size_t __refs = 0); 414 415 explicit 416 codecvt(__c_locale __cloc, size_t __refs = 0); 417 418 protected: 419 virtual 420 ~codecvt(); 421 422 virtual result 423 do_out(state_type& __state, const intern_type* __from, 424 const intern_type* __from_end, const intern_type*& __from_next, 425 extern_type* __to, extern_type* __to_end, 426 extern_type*& __to_next) const; 427 428 virtual result 429 do_unshift(state_type& __state, 430 extern_type* __to, extern_type* __to_end, 431 extern_type*& __to_next) const; 432 433 virtual result 434 do_in(state_type& __state, 435 const extern_type* __from, const extern_type* __from_end, 436 const extern_type*& __from_next, 437 intern_type* __to, intern_type* __to_end, 438 intern_type*& __to_next) const; 439 440 virtual 441 int do_encoding() const throw(); 442 443 virtual 444 bool do_always_noconv() const throw(); 445 446 virtual 447 int do_length(state_type&, const extern_type* __from, 448 const extern_type* __end, size_t __max) const; 449 450 virtual int 451 do_max_length() const throw(); 452 }; 453#endif //_GLIBCXX_USE_WCHAR_T 454 455 /// class codecvt_byname [22.2.1.6]. 456 template<typename _InternT, typename _ExternT, typename _StateT> 457 class codecvt_byname : public codecvt<_InternT, _ExternT, _StateT> 458 { 459 public: 460 explicit 461 codecvt_byname(const char* __s, size_t __refs = 0) 462 : codecvt<_InternT, _ExternT, _StateT>(__refs) 463 { 464 if (__builtin_strcmp(__s, "C") != 0 465 && __builtin_strcmp(__s, "POSIX") != 0) 466 { 467 this->_S_destroy_c_locale(this->_M_c_locale_codecvt); 468 this->_S_create_c_locale(this->_M_c_locale_codecvt, __s); 469 } 470 } 471 472 protected: 473 virtual 474 ~codecvt_byname() { } 475 }; 476 477 // Inhibit implicit instantiations for required instantiations, 478 // which are defined via explicit instantiations elsewhere. 479#if _GLIBCXX_EXTERN_TEMPLATE 480 extern template class codecvt_byname<char, char, mbstate_t>; 481 482 extern template 483 const codecvt<char, char, mbstate_t>& 484 use_facet<codecvt<char, char, mbstate_t> >(const locale&); 485 486 extern template 487 bool 488 has_facet<codecvt<char, char, mbstate_t> >(const locale&); 489 490#ifdef _GLIBCXX_USE_WCHAR_T 491 extern template class codecvt_byname<wchar_t, char, mbstate_t>; 492 493 extern template 494 const codecvt<wchar_t, char, mbstate_t>& 495 use_facet<codecvt<wchar_t, char, mbstate_t> >(const locale&); 496 497 extern template 498 bool 499 has_facet<codecvt<wchar_t, char, mbstate_t> >(const locale&); 500#endif 501#endif 502 503_GLIBCXX_END_NAMESPACE_VERSION 504} // namespace std 505 506#endif // _CODECVT_H 507